Sloped gable roof rafters. How to make a gable roof truss system with your own hands. Video - Manufacturing and installation of rafters on a gable roof

Roof installation is a fairly complex construction process. For self-assembly and installation of the rafter system, you need to know how to properly connect the elements, what should be the length of the rafters, at what angle they should be tilted and, most importantly, what materials the roof is assembled from. Without special knowledge and skills, making a complex roof will be problematic. In this case, you can choose the best option - a gable roof with your own hands.

Design features of a gable roof

The gable roof is based on a triangle, which gives it rigidity. It contains the following elements:

Mauerlat- these are bars laid directly on the outer walls around the entire perimeter of the house. The fastening of these elements is most often carried out by means of anchor bolts. The recommended material for the manufacture of elements is softwood. The cross section of the bars has the shape of a square with sides of 100 * 100 mm or 150 * 150 mm. It is on the Mauerlat that the rafters lie, and the load from the entire system is transferred to the outer walls.
Sill- this is a beam of a certain length, against which the racks abut. It is laid in the direction of the internal load-bearing wall. The element is used in the arrangement of the roof on large houses.
Struts- these are elements made of small bars. They are installed at an angle between the rack and the rafters. This arrangement helps to strengthen the rafters and increase the bearing capacity of the roof.
Racks- these are roof elements located vertically. Through this element, the load from the ridge beam is transferred to the walls. Racks are located between the rafters.
Puffs are beams that connect the rafter legs at the bottom. This element is the base of the truss triangle. Like struts, these beams make wooden roof trusses stronger and more resistant to various loads.
rafter legs they are boards of a certain length, having a section of 5 * 15 cm or 10 * 15 cm. The elements are connected to each other at an angle, forming the top of a triangle. Two connected rafter legs are called a truss. The number of such structures is determined by the length of the house. In this case, the distance between farms can be no more than 1.2 meters and not less than 0.6 meters. When calculating the step of the rafter legs, the total weight of the roof, wind and snow load should be taken into account.
Skate is located at the highest point of the roof and is a bar that serves as a connection for the slopes. This element is supported from below by vertical racks, and the ends of the rafters are attached to it from the sides. In some cases, instead of timber, two boards are used, connected at a certain angle and nailed to the top of the rafters on both sides.

A do-it-yourself gable roof involves making a crate from boards or timber, which are hammered onto the rafters in a perpendicular direction. Depending on the material for the roof, the crate can be solid or with gaps.

What is the difference between layered and hanging truss systems

Before you assemble a gable roof, you need to know some of the features of its structure. A hanging truss system is arranged when the house is small and there is no internal load-bearing wall. In this case, the rafters are connected at a certain angle, making appropriate saw cuts at their ends, nails are used for connection.

When constructing such a rafter system, the racks and the ridge are not made, and the emphasis of the lower ends of the rafters falls on the external load-bearing walls. To make the structure more durable, the upper puff should be located no further than 0.5 meters from the top. Sometimes floor beams are used as puffs. The absence of racks frees up attic space, which allows it to be used for arranging the attic floor.

If the house has an internal load-bearing wall, then it is more efficient to use a layered truss system. In this case, the bed is laid, the support posts are fixed on it, onto which the skate is nailed. This method is considered to be simpler and more profitable from the material side. When designing ceilings at different levels, the racks can be replaced with a brick wall, which will divide the attic space into two parts. A gable roof can also be made with different slopes along the length, which is also very beautiful and practical.

Do-it-yourself gable roof installation process

To answer the question of how to properly make a gable roof with your own hands, you need to follow the sequence of actions.

Installation of this type of roof involves work according to the following plan:

Preparatory stage.
Mauerlat fixing.
Farm assembly.
Installation of trusses on floors.
Skate device.
Stuffing the crate.

Preparatory stage

Before starting work, you should prepare a set of necessary tools and materials:

Hammer and hacksaw.
Square and level.
Fasteners.
Boards, beams and roofing material.

All wooden materials should be treated with antiseptic solutions and flame retardants and dried well.

Mauerlat installation

In houses made of wooden logs or timber, the top row of the log house plays the role of the Mauerlat, which makes the process easier. On the inside of the log, a groove is cut into which the rafter leg is installed.

In brick or block houses, the Mauerlat is laid as follows:

When laying the last rows, threaded metal studs are mounted in the masonry. They should be located around the entire perimeter of the house at a distance of about 1.5 meters from each other.
The upper part of the walls is covered with roofing material in several layers, piercing it with studs.
Holes are drilled in the beams in accordance with the location of the studs.
Beams are laid, putting them on studs. At this stage, it is important to ensure that the beams are laid exactly horizontally, and the opposite elements are parallel to each other.
Nuts are tightened on the studs, pressing the Mauerlat. See also: "".

The result of this stage should be a rectangle of the correct shape, located on the same horizontal line. This design makes the structure more stable and facilitates subsequent work. The completion of the work is cutting grooves in accordance with the size of the rafters.

Hanging truss system

The length of the rafters is determined by the distance between the external load-bearing walls and the angle of connection of the rafter legs. The optimal length is 4-6 meters, given the eaves overhang of 50-60 cm. These parameters should be taken into account when solving the problem of how to make a large roof.

At the top, the rafters are fastened in different ways: end-to-end, overlapped or "in the paw" with cut grooves. The rafters are fixed with bolts or with the help of metal plates. A puff is mounted a little lower and the finished truss structure is lifted to the installation site.

First, trusses are installed along the edges, checking their verticality with a plumb line. At the same time, the overhang is adjusted. The rafters are attached to the Mauerlat with bolts or steel plates. Sometimes temporary braces are used to support the truss during installation. Inserting the remaining rafters, maintain the same distance between them. After installing and fixing all the trusses on both sides of the upper slope, I nail boards with a section of 5 * 15 cm.

Methods for fixing hanging rafters on the Mauerlat

Hanging rafters can be attached to the Mauerlat in several ways:

A groove is cut out on the rafters, and a metal pin is driven into the wall at a distance of 15 cm from the upper edge. The rafter is placed on the Mauerlat, tied with wire and pulled to the wall. The wire is wrapped around the pin.
The second method involves laying out a brick stepped cornice. At the same time, Mauerlat is laid along the inner edge of the wall and a groove is made in it for the rafter leg.
When using the third option, the rafters rest against the floor beams, which have an outlet for the perimeter of the house up to half a meter. Beams are cut at an angle and fastened with bolts. Using this method, a do-it-yourself roof is assembled without a Mauerlat.

How to install layered rafters

Rafter rafters are installed in the following order:

The load-bearing wall, located in the center of the house, is covered with waterproofing material.
A bed is laid on top and fastened with bolts or metal brackets.
Racks of bars with a section of 10 * 10 cm are put on the bed.
Runs are nailed on top of the racks in the horizontal direction, strengthening the structure with temporary struts.
Perform the installation of rafters and their fixation.

After installing the main structural elements, wooden surfaces are treated with fire retardants.

How to make a crate

Before laying the battens, the rafters are covered with a layer of waterproofing, protecting it from getting wet. Waterproofing is laid in a horizontal direction, starting from the eaves and rising up. The strips are laid with an overlap of 10-15 cm, the joints are sealed with adhesive tape.

A ventilation gap is required between the crate and waterproofing; for this, slats no more than 4 cm thick must be filled on each rafter leg.

Now you can sheathe the truss system. The crate can be made from a 5 * 5 cm timber or boards having a thickness of not more than 4 cm and a width of more than 10 cm. Start filling the crate from the bottom of the rafters, maintaining a certain step.

After installation, the battens begin to sheathe the gables and overhangs. Depending on the construction budget and the desire of the homeowner, you can make a gable roof with gables made of plastic, corrugated board or wooden boards with your own hands. Knowing how to sheathe the gable of the house with a profiled sheet, you can do the installation yourself. Sheathing is attached to the sides of the rafter leg, using nails or self-tapping screws. Overhangs can be sewn with all sorts of materials.

The truss system of any object is equivalent to the value of the load-bearing structural elements of the house. The roof plays the role of a node under which the stiffening ribs of the building are assembled. Accordingly, when installing the roof with your own hands, it is required to give the maximum value to all structural units, even when using a simple option - gable.

Advantages of gable roofs

There are a lot of options for pitched truss systems. Among them, simple symmetrical is especially popular. Why? Here are her virtues:

On the basis of a gable roof, variations are created to reflect the special architecture of the building.
Simple calculations, easy to understand.
The one-piece design creates favorable conditions for the dryness of the internal space and the unhindered flow of water, snow and ice.
The maintainability, strength and durability of a gable roof are much higher than other options.

Depending on the size, homeowners always have the opportunity to equip the under-roof space, make it a full-fledged floor or attic. In a word, a gable roof is the right and profitable solution for any object, whether it is a residential building, a summer house or a bathhouse.

Elements of the truss system

Depending on the type of roof, structural elements vary. Without knowledge of the appointments of each, it is impossible to arrange a reliable coverage at home. Let's analyze in detail:

Mauerlat

The basis of the truss system. It is a beam with a section of at least 150 mm, or an I-beam channel, if the roof structure is metal. It is located on the bearing walls of the object. Its purpose is to distribute the load of the system evenly throughout the structure of the house.

Rafter leg

Structural basic unit of the system. Together with others, it forms a truss system - strengthening the strength of the entire roof. It is made of a wooden beam, which is not inferior in cross section to Mauerlat or profile pipes.

Rafter rack

Vertical bar or pipes. Depending on the variant of the gable roof, the pillars can be located in the center and / or on the sides. They take part of the weight of the entire truss system, which is why the cross section is 150 mm.

Rafter girders

Horizontal beams laid on racks and under the ridge to support the rafter legs. They provide structural rigidity and relieve stress on trusses.

Puffs and braces

Connecting beam for rafters. The action is similar - relieving the stress of a beam or metal and making the structure rigid.

lying down

Mounting support for racks and struts. To securely connect these two elements, you need a large cross-section beam - 150 mm or a thick-walled pipe of impressive diameter.

Lathing beam

Elements laid perpendicular to the rafters. Serve to install the selected roofing and create a multilayer protective cake. The cross section is small - 40–50 mm.

If the planned roof structure is made of wooden beams, you should carefully consider the quality of the wood upon purchase - the beam should not have knots interspersed, be made of soft wood.

Also, wood must have natural moisture, otherwise it will begin to dry right in the system structure, cracking, deforming the roof model, depriving it of reliability and safety.

Calculation of the truss system

A gable roof is a complex structure. The project takes into account many factors - natural nuances, wind, constant and variable loads. It is extremely difficult to make calculations on your own, without special knowledge about the climate of the area, the characteristics of the material for the manufacture of the system, and the nuances of pressure distribution.

Ideally, the calculations are at the mercy of professionals, you can independently choose only the material for coating - the following parameter depends on its type:

Tilt angle

The minimum angle of inclination of the roof relative to the parallel of the earth is 5 degrees. However, its dependence comes from the chosen roofing material. In this capacity, traditional slate, profiled sheet, flexible and metal tiles are used.

They are guided by the following rule: the steeper the slope, the more textured the roof can be.
From 5 degrees for laying rolled protective insulation of the roof. The number of layers matters - up to 15 degrees three-layer coatings, above - two- and single-layer coatings.

From 6 - ondulin.
From 11 - slate.
From 12 - corrugated board.
From 14 to 20 - metal tiles.
From 15 to 45 - soft roof.

Thus, the resulting precipitation - snow, water - will not linger on the surface, although complete cleaning requires one's own efforts or the involvement of specialists for the installation of the Anti-Ice system.

Determining the parameters of the rafters - step, length, section

The rarer the step, the more impressive the cross-section of the beam or the diameter of the pipes should be. As a rule, for load-bearing structures, this parameter is at least 150 mm, 100 mm - for country houses and related construction - gazebos, bathhouses, outbuildings.

Next, you need to set the number of rafters per slope: its length is divided by the installation step, which is from 60 to 100 cm + 1 extreme leg. Multiplying the result by 2 gives the total. Depending on the section of the beam, the amount of rafter legs and the installation step vary.

The length of the rafters is simply calculated if the school knowledge about the right triangle is left in the luggage. The rafter leg is equal to the hypotenuse of the resulting figure. The calculation is as follows: A² + B² = C², where - A is the height of the roof, B is half the length of the pediment, C is the length of the rafter leg. To the resulting value is always added from 30 to 70 cm for cornice overhangs.

Types of truss systems

Before getting down to work, it is important to choose a truss system option for a gable roof. There are few of them, each has its own advantages and disadvantages:

hanging

Suitable only for a standard roof width of 6 m, respectively, this is the length of the rafter leg. Fastening occurs by fixing the ends to the ridge run and the bearing wall. Be sure to install a puff that levels the stress and pressure of the structure.

In addition, they will play the role of load-bearing beams. Without them, the structure will disperse under weight. The advantages of the option are in the absolute dryness of the roof surface during the off-season, and in less deformation at the time of shrinkage.

Layered

The option is suitable for any roof width. Reliability and stability is ensured by fixing the bed to the Mauerlat. Thus, the pressure is leveled by the rack, which reduces the tension in the rafter legs. The advantage of the system is simplicity, but the design requires large investments - additional lumber is required to equip the beds.

hybrid

These systems are typical for multi-pitched roofs, where transitions are accompanied by numerous reinforcements, beams, posts, beds, slopes and other elements for the stability of the entire structure. The device is expensive and complicated, so only a professional should deal with the project and construction. At least curate it.

Do-it-yourself installation of a gable roof

So, when the option of the truss system is selected, lumber is purchased, a roof project is drawn up, you can get to work. You cannot deviate from the sequence of steps. This threatens to delay installation and loss of structural reliability.

Mauerlat mount

If the length of the beam for installing the Mauerlat is insufficient, an extension is made. Using the half-tree cutting method, the ends are connected. Additional fasteners are anchor bolts. Do not use self-tapping screws, dowels or nails - they are unreliable. Mounting to the wall is as follows:

There must be a margin of at least 5 cm from the edge.
Holes are drilled along the wall for inserting fasteners. Similar actions are carried out with a bar.
Mauerlat is attached to the edge with steel studs. The fastening step is more often 2 times than the distance between the rafter legs. Subsequently, before installing the main units, they are guided by metal marks.

Important - before laying the Mauerlat, the edge of the wall is protected with waterproofing. Spread one layer even if the house is made of wood.

Making and fixing rafters

Roof trusses are convenient in that they can be assembled on the ground into a finished structure and moved to the roof. This will reduce installation time, however, the model is heavy and lifting equipment will be required, which, of course, will increase the cost of the project.

For budget construction, another method is suitable:

At the bottom and top of the rafter legs, a gash is made to attach to the Mauerlat and the ridge run. This must be done separately with each unit, after lifting the wood up.
Places for fixing are marked on the Mauerlat and a ridge run is installed: racks are installed along the gables, on which a beam is placed. If the length is not enough, it is increased, but in a different way, unlike the Mauerlat - a board is screwed to the junction from both sides.
Depending on the chosen model of the truss system - layered, hanging - they make cuts in the ridge beam, Mauerlat or drill holes in them for fasteners.
Next, begin the installation of rafter legs from opposite ends of the roof, gradually moving towards the middle. Between the corners of the extreme trusses, it is not bad to stretch the cord to exactly match the entire horizontal part.
Between themselves, the rafter legs are connected by puffs and struts. Under the ridge part, at the angle formed by the rafters, wooden linings are stuffed, and the ends themselves are tightened with bolts.

More recently, professional builders have begun to use sliding fasteners for roof installation. Metal plates securely hold the bearing elements and at the same time move due to shrinkage. This cancels out its consequences.

The work of fixing the rafters is hard and long. You should calculate the time in advance - you can not leave the roof unfinished during the rainy season, otherwise the rigidity of the structure will be lost in the future due to absorbed moisture.

Gables and framing

The side parts of the roof - gables, are made in the form of ready-made shields from boards and are completely installed at the top. Difficulties should not arise - it is only important to carefully file them at the required angle. It is necessary to fasten the crate only after the final appearance of the roofing is known. For example:

Under the corrugated board, the step of the crate beam will be 440 mm.
The metal tile is fastened to the crate in increments of 350 mm.
A soft roof needs a solid plywood coating.

It is important to note the places for the passage of the chimney - the crate should not come into contact with a brick or metal surface. The distance to the hot unit is at least 15 cm. Before installing the lathing, the finished roof is covered with waterproofing with allowances extending beyond the edges of the walls. Then the beam is mounted.

If it is decided to make a warming cake from above, then first the vapor barrier is strengthened from the inside, then the selected material is put into the boxes formed by the rafters. Next, waterproofing and wind protection.

Then it is required to re-mark the contours of the rafter legs with a beam 20 * 20 and then fill a new layer of the crate, along which the roofing material will be laid - the formation of ventilation ducts. This method will save the capacity of the under-roof space if the owners are going to use it for a specific purpose.

Roofing material flooring

Regardless of the type of roofing raw material, installation starts from the edges of the roof and leads it up, laying one unit on top of the other. Thus, rain moisture will not get under the material.

The method of fastening depends on the type of material - soft tiles or tiles with a bitumen or polymer base are fused. Solid profiled sheets - ondulin, metal tiles - are fixed in pre-drilled holes to the crate, using rubber pads to seal and preserve the anti-corrosion layer.

As a result: the description of the installation of the truss system and the roof is easy only on the screen or paper. In reality, the process is complex and multifaceted. Therefore, if knowledge is not enough, it is better to invite professionals to work - their work is always guaranteed.

The gable roof truss system is considered one of the simplest in purely constructive terms. It consists of only a few elements, the number of which decreases or increases due to the size of the roof itself. But with apparent simplicity, the process of erecting a gable roof itself requires knowledge of some of the nuances that affect the quality of the final result.

Rafter system for a gable roof

What is a gable roof

From the name it becomes clear that the roof structure is two slopes that have a rectangular shape in the plane. More often, the slopes have the same dimensions, but there are so-called asymmetric designs in which the slopes differ in size from each other.

In this case, the slopes are set to each other at a certain angle, which is called the slope. The line of contact is the ridge beam, which is part of the truss system. In a simple way, it is called a ridge, and it is the highest point of the roof.

The side planes formed by the slopes are called gables. They are triangular in shape. After the construction of the roof, the sidewalls are lined with sheet or panel materials: plywood, OSB, even boards, etc.

What is a gable roof truss system

The basis of the structures of the slopes are rafter legs, they are also rafters. They are made either from lumber (beams, boards), or from a steel profile (corner, channel). In private housing construction, wood is used. It is easier to work with, plus lumber is cheaper.

The device of the gable roof truss system is not only rafters. In addition to them, there are several other mandatory elements. The photo below shows all the elements of a gable roof. Let's designate them.

Each of the elements of the roof has its own purpose.

Elements of the gable roof truss system

Mauerlat. In fact, this is a beam on which the rafters rest. Its purpose is to evenly distribute the load from the rafters on the walls of the house. If the Mauerlat is not used, then the rafters will put pressure on the walls pointwise, that is, large stresses will arise at the installation sites, which will lead to cracking of the walls.

rafters installed at an angle.

Skate, he is a ridge beam or run. Its task is to form a place for joining the rafter legs. A ridge beam is an optional element of a gable roof. There are designs in which it is not installed. But more on that below.

Puffs. They are not always used, but only on hanging rafters or if the rafter system is installed on a wide house.

floor beams that form the ceiling in the room and the floor in the attic.

One of the floor beams, which is called lying down. It additionally functions as a base for the support posts that support the rafters. Not always used.

Support legs, they are grandmas supporting the rafter legs. They are installed only if the span of the house is at least 6 m.

Struts, they are also diagonal props. They are used only if the support posts cannot ensure the overall reliability of the truss system.

There is another element that is clearly visible in the photo below. These are support posts for the ridge run. They are installed if the design of the truss system is heavy. That is, the entire structure is assembled under heavy roofing material, for example, under ceramic tiles.

Sloped rafters with support posts under the ridge run

You might be interested! A warm roof is an important detail in the construction of an energy-efficient home. From the article at the following link you can find out.

Types of rafters

The roof truss system (gable) can be assembled from layered or hanging rafters.

Layered

They got their name because the lower ends rest on the walls of the house, the upper ends on the ridge run. In this case, the truss elements are subjected to loads that bend them. The design is reliable, durable, with a large bearing capacity.

The photo above just shows the rafter system of a layered type. It is clearly seen that the legs rest in the upper part on the skate. In this case, there are two types of fastening of the rafters themselves in the upper part:

fastening is made to the ridge:

fastening is made between each other with an emphasis on the ridge (photo above).

hanging

It is necessary to immediately indicate that this type of truss system can be used if the distance between the walls of the house does not exceed 12 m. Because the rafters abut the lower ends against the walls, and the upper ends only between themselves (there is no ridge run in the structure). Hence the low bearing capacity with a large expansion.

Hanging rafters for the roof have one purely design flaw - a large support load on the walls of the house. To reduce it, puffs are installed between the legs to form a rigid triangle. Often, the functions of the puffs are performed by the load-bearing floor beams.

If necessary, strengthen the hanging rafters, install racks and struts under them.

Hanging gable roof rafters

Installation of a gable roof truss system

Two types of truss system determine two types of their assembly technology. Let's consider each separately.

Installation of layered rafters

There is a certain sequence for assembling layered rafters.

Two extreme support posts are installed under the ridge beam. They will not only support the beam, but also be the elements that form the gables of the building. Attach them at the bottom to the Mauerlat. At the same time, they are strictly set vertically, and the upper ends are in the same horizontal plane. To do this, a strong thread is pulled between the racks, the level is checked for horizontalness. If there are deviations, then one of the supports (low) is raised using wooden supports.

Intermediate support posts are mounted along a horizontally stretched thread in increments of 2-2.5 m. To prevent the beams of the racks from moving, they are supported with temporary fasteners: props or puffs.

A ridge beam is laid on the racks, which is attached to them.

Produced in pairs installation of gable roof rafters. Installation can be started from either side. Fastening is immediately carried out to the Mauerlat and to the ridge. The main thing is to maintain the distance between the legs, which is determined depending on the severity and bearing capacity of the roofing material. Usually this parameter is indicated in the project of the house.

If necessary, intermediate support posts and struts are mounted.

Installing rafters on a ridge along a stretched thread

Installation of hanging rafters

The technology for installing hanging rafters is different. To do this, the entire structure, assembled from two rafters and puffs, is assembled on the ground. That is, roof trusses are prepared in the required quantity, which then rise to the roof. Sometimes craftsmen assemble trusses on the roof. Collected one - installed, collect the next.

It should be noted that such farms have a significant mass. Lifting them manually is difficult and dangerous, so they use the services of a crane. And this increases the cost of construction.

Hanging trusses assembled on the ground

The most difficult thing is to set farms. All of them are installed at the installation site with a planned step, where they are temporarily fixed with jibs and props. Then a thread is pulled between the extreme farms. It must be set so that, firstly, it is stretched strictly along the horizon, and secondly, according to a design that is higher than the rest.

It remains only to raise the truss structures, which turned out to be below the stretched level. And the last - the installation of the crate, which will secure all the trusses into one truss system. Please note that at the bottom of the rafters will be fixed to the Mauerlat.

You may be interested! When the installation of the truss system is completed, the turn of roofing comes. From the article at the following link you can find out.

Rafter calculation

length of rafter legs;

the step of their installation;

section of the lumber used.

Everything is simple with the length, for this you will have to use the Pythagorean theorem, which is based on the formula: c 2 \u003d a 2 + b 2, where c is the hypotenuse of the triangle (this is the rafters), a and b are the legs. The latter are the height of the roof and half the width of the house. All parameters can be easily measured.

The length of the rafter is l 2 + H 2

It is more difficult with the installation step, because a lot will depend on the mass of the roofing material and the loads from natural precipitation. The larger both loads, the smaller the installation step. But, as practice shows, this parameter varies from 60 cm to 2 m. The latter indicator is used if corrugated board with large corrugation parameters, for example, H75, is used as a roofing material.

As for the section of the rafter legs, here, as in the case of the installation step, loads are taken into account, as well as the length of the legs and their installation step. Here the dependence is as follows: the greater the load, step and length, the larger the cross section.

Video description

In the video, the installation process of the truss system:

And one moment. Rafters for a gable roof are laid at a certain angle (indicated by the letter “a” in the photo). The slope is selected with the calculation of the choice of roofing material. That is, some coatings cannot be laid on roofs if the angle of inclination is less than required. Here are some ratios:

the minimum angle of inclination of the truss system for slate is 22 °;

for corrugated board - 12 °;

for metal tiles - 14 °;

soft tiles - 15 °.

The ratio of the roof slope to the type of roofing material

On our website you can find contacts of construction companies that offer a turnkey roof design and repair service. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

Generalization on the topic

Gable roofs are traditional designs. But from the article it becomes clear that there are two truss systems that form the basis of the construction of roofs. The one that fits the size of the house is selected. As a selection criterion, the loads that put pressure on them are also taken into account. Therefore, it is important to correlate everything correctly, taking into account the nuances of construction processes.

In any pitched roof there is a system with inclined planes (slopes). The selection and calculation of the truss system must be done taking into account the supports necessary for it, as well as the type of roof, dimensions and shapes of the structures to be covered. Having calculated the truss system of a gable roof, you can choose the right size of the rafter leg, as well as ensure the high strength of the roof.

Types and arrangement of the gable roof truss system

This system should be chosen from the conditions and the number of supports, as well as the distance between them.

For example, layered types of rafters will be supported by the load-bearing walls of structures (from the outside), as well as on additional. supports inside, if suddenly there will be more than four and a half meters between the main ones. In the lower part, the rafter leg rests on beams that transfer weight between the roof and the wall of the structure. As for the upper end, it is connected to the ridge type of run, as well as to another rafter leg.

The hanging truss system of a gable roof has a puff located at the level where the lower support nodes are located, and maybe higher than they are. There are no intermediate supports. As for the distance between the carriers from the outside, it should be up to six and a half meters. This option refers to a triangular farm, and between them the distance according to the plan is from 1.3 to 1.8 meters.

Coatings

Eternite types of roofing - fibrous or flat asbestos-cement sheets. They are cheap and easy to install.

Slate refers to slate roof options, they are made from natural materials of layered slates. Slate also includes ondulin and euroslate.

Metal coatings are used to cover residential buildings. They will reliably protect from the effects of the atmosphere, are not heavy and are easy in terms of installation work. These include aluzinc, galvanized and corrugated board.

Roll type refers to a soft roof. It has the property of not letting in moisture, and is very resistant to negative environmental influences. They are also easy to install. This includes roofing material, bito-polymer material, membrane roofing.

Some use wood roofing. But very rarely, because they are difficult in terms of installation.

Roof options that transmit light are made of glass, polymer.

We crate

It is the crate - the foundation of the roofs. It is made from beams or wooden boards. If a wooden, metal, tiled roof is being equipped, a beam is selected, the cross section of which is:

5 by 5 cm, if the distance between the rafters in the range of one meter is 1.1m).

5 by 6 cm, if the rafter pitch is from 1.2 to 1.3 meters.

6 by 6 if the step is 1.4 or 1.5 meters.

In other cases, boards can be up to 2.5 cm thick.

From wood, log options are used, which are cut down literally on one edge. In order to make layered rafters, a section of a round log with a diameter of 12 to 20 cm is more suitable.

How to calculate the desktop rafter leg?

Between the legs there can be a distance from a meter to one and a half. Their cross section must be determined in accordance with the calculations. For this, the strength and rigidity of structures are recognized. Therefore, you need to find out what is the constant load on the rafters, which includes regular loads and snow, per linear meter.

To carry out calculations, you need to know such data as:

The step with which the rafter legs are installed
What is the angle of the roof
What are the dimensions of the roof

What parameters will be chosen and, in general, many coefficients, depends on the chosen material for the roof and its detailed composition.

It should be borne in mind that there must be a reliable pairing between the runs and the rafter legs. Thanks to this, the walls of structures will not be destructively torn open. If you have wooden structures, they need to be inspected periodically.

Variants of gable roofs are quite common today. But having properly equipped the roof, you will have a strong, beautiful and very durable housing!

Rafter system - strong roof frame for holding roofing and other elements.

How well the roof frame is arranged depends on the strength of the roof as a whole.

Otherwise, its functionality, the ability to protect the building from external influences and provide heat in the house may deteriorate.

Therefore, you need to correctly approach the choice of truss systems and correctly draw up a rafter plan.

And you can read how to calculate the truss system.

Depending on the purpose of the room, the dimensions of the gable roof, the device of the truss system is classified as follows: hanging system and layered.

Hanging system

Hanging rafter gable roof system It is supported only by the load-bearing external walls of the building.

Depending on the width of the span, the roof project, the installation of hanging systems has features.

For small houses

It is advisable to erect a hanging structure for buildings where the distance from one wall to the opposite does not exceed 6 meters. The frame looks like a triangle.

To strengthen the bearing capacity of the faces of the frame triangle, several methods are used:

The bases of the rafter legs at the top are fixed with overlays;
Use bars of a larger section on the side parts;
The bars are fixed by cutting them into the ridge element;
The slopes for the canopy equipment are built up by cutting an opening for the frame beam in the extended boards so that they converge behind the line passing from the edge of the inner wall to the slope of the rafter.

Using these methods, it is possible to distribute the load throughout the structure.

Strengthening the frame triangle

For mansard roofs

When arranging the frame under, you should pay attention to some points:

Mandatory installation of the Mauerlat, on which the frame beam is installed by cutting;
Installation of a crossbar - the basis for a ceiling canopy of a floor. The most effective mounting option is to cut the crossbar into the rafter with a semi-swing;
The length of the bevel board should be longer than the wall line;
The cross section of the frame bars should be maximum;
The puff should be secured with a suspension. With a long tightening, it is required to strengthen it in the center with the help of nailed boards from above and below.

CAREFULLY!

Particular attention should be paid to the fastening of the elements, since the attic is under load from the outside and inside.

In addition, the truss system of a gable roof with an attic is equipped with heaters, which increases the load.

Rafter frame for mansard roofs

For big houses

With a span of more than 6.5 meters, the installation of a hanging system requires the installation of more fixing elements in order to prevent sagging of the tightening, which causes its own weight.

Points to consider:

It is advisable to make a puff from two bars by cutting, secure with metal plates;
In the central part of the frame, a headstock should be installed;
For a confident distribution of gravity to the headstock and rafters, it is better to attach struts, as well as other holding elements.

When installing a suspension-type system, it can sometimes do without mounting a Mauerlat and limit itself to installing boards on a film. In addition, the hanging system is distinguished by the absence of complex nodes, which facilitates the work on arranging the roof frame.

Hanging system

Layered system

The difference between a layered type structure and a hanging one is that the structure has additional support points inside the room. A prerequisite for installing a layered system is the installation of a Mauerlat.

The design of the system provides for the installation of both expansion and non-expansion frame.

Strutless frame

A non-expanding frame should be installed in houses with log walls. When installing rafters, their bases must be attached to the Mauerlat.

Options for attaching the base of the system to the Mauerlat:

By beveling the sole of the rafter leg in such a way that its area with the Mauerlat is the same, and the cut does not exceed 0.25 cm of the height of the beam. At the same time, the rafters, without connecting to each other, are attached to the ridge element on both sides;
By connecting with one nail the rafters at the ridge - at the top, and swivel with a flexible metal plate to the Mauerlat - at the bottom.

When attaching rafter legs without connecting them in the ridge part special attention should be paid to the accuracy of calculations.

Even with minor discrepancies in the scheme, the expansion pressure will act on the walls of the building, which can lead to the collapse of the walls.

Strutless frame

With contractions

To strengthen the structure and give it stability, fights are mounted to the racks of the structure. You should use a beam of the same section as for the rafters. To increase the strength of the fight, they are nailed on both sides of the timber.

The same mounting option is effective for firmly fixing the ridge element, which prevents the roof from moving in a horizontal direction.

Frame with contractions

with braces

Struts reinforce the bearing capacity of the wooden frame and ensure the strength of the rafter board.

An important requirement when installing the strut is a correctly measured cut angle, which makes it possible to fit the strut tightly to the connected elements.

ATTENTION!

If, with a layered system, the supporting part is located in the center of the frame base, then the brace is attached at an angle of 45 ° to the horizontal line, if the support is closer to one of the load-bearing walls, then the attachment angle may be different: from 45 ° to 53 °.

It is advisable to erect a frame with struts in places where there is a possibility of planting a foundation, or in wooden buildings where a slight shrinkage of the walls is acceptable.

Frame with braces

With two supports indoors

When there are two supports in the form of internal walls, then when arranging the rafter legs, beams are placed under them. If the beams are not installed, then a rack resting on an internal support is nailed to the base of the rafters.

The rafter beams are installed on load-bearing supports. On the supports inside the room, beds are installed, on which the load from the rafter beams from the racks falls. The rafters are cut so that they fit snugly against each other, and fixed.

With this design, the ridge run is not installed.

To ensure the rigidity of the structure, puffs are attached.

The stability of the structure is ensured by means of racks, which are installed horizontally from the inner base to the rafter leg, and jointing - wooden beams that connect the bases of the racks obliquely.

If the structure is spacer, then a beam is attached above the girder, connecting the frame legs - a crossbar.

Layered system

Types of truss systems

Mansard roof rafters

Before installing the truss system under the attic, it is necessary to correctly calculate the load of the roof and take into account other factors, which may affect its functionality. All wooden elements must be treated with antiseptics.

Installation of the truss system is carried out in stages:

Install the Mauerlat on the waterproofing layer. They fasten the board to the walls with staples or nails and tie it with metal wire to hooks prepared in advance in the wall;
Frame elements are cut;
The main rectangle is made from puffs and racks;
Two middle runs are mounted, to which the lower rafters are attached;
The structure can be raised to the roof, where the upper rafters are already installed, connecting them at the upper base, securing the ridge beam and the side run;
Reinforce the structure with the necessary elements: puffs, racks, struts, additional stops.

After installing the frame, a vapor barrier film is laid on it, elements and a covering material are installed.

Mansard roof device

The device of rafters for the attic

The gable roof attic has the simplest hanging system.

For the attic floor, it is advisable to make ready-made trusses on the ground, and then raise them to the roof, after installing the Mauerlat.

The trusses consist of rafter legs, firmly fixed by tightening at the lower base. You can additionally use struts or headstock.

Of great importance is the fastening of puffs on the rafters. It is recommended to install puffs so that their bars are located half a meter behind the wall line, then there is no need to additionally install an overhang.

You can read how to make rafters yourself.

Farms are fixed with the help of upper and lower runs.

Rafter system for the attic

Gable roof truss system: elements

When arranging the frame of a gable roof, elements are used:

Mauerlat. An element that is attached to a load-bearing wall. The entire structure of the truss frame is mounted to it;
Run. A beam connecting the rafter legs on the sides and in the ridge element;
Puff. A beam attached to the rafter legs, preventing their divergence;
Grandmother. A beam located vertically and fixed at the ridge and puff;
Strut. Plank connecting at an angle the bed and the rafter;
Rack. Vertically rests on the bed and rafters;
. Beam connecting the upper bases of the rafters;
filly. The built-up part of the rafter for the overhang;
Overhang. Additional design, serves to protect the outer wall from rain;
Crate. Lattice installed on the truss frame for attaching the top layer.

The combination of several elements (rafters, racks, braces) in one plane is called a truss.

Gable roof truss system, drawings and photos below:

Drawing of the elements of the truss system

Knots of the truss system of a gable roof

Reliable fastening of structural units provides strength and endurance of the structure, increases its service life.

The strength of the base of a gable roof depends not only on proper fastening.

It also consists of the correct calculation of all elements of the frame, from the verified definition of the type of structure at the design stage.

Rafters for a gable roof are connected to different structural elements.

The main components of the design:

With beam: fasten either with a spiked tooth or a tooth with an emphasis. Additionally, corners are used. They are mounted to the beam by cutting out an emphasis for the spike in the beam with a socket. A single tooth is attached with a spike and an emphasis. If a cut is made, then the distance from the edge of the bar should be 0.2 - 0.4 m;
With Mauerlat: with rigid fastening, corners are used or washed down, which is fixed with nails or staples, when hinged - moving metal fasteners, when washed down - a nail or staple;
With skate: cutting off the edge at an angle, fasten end-to-end with nails, fastening with a bracket or patch board. Overlapped boards are fastened with a bolt or studs.

Depending on the span, the elements are fixed:

grandmother. Top - with brackets and a collar, bottom - with a collar;
Strut. The top is attached to the rafter, the bottom - to the headstock;

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